Answer for Solid State Devices

 

1. Atom is a smallest particle of an elements. Every one of the elements is made up of atoms with its own structure

2. The basic particle of negative charge is electrons while proton is the basic particle of positive charge.

3. A typical atom consist of proton, neutron and electron.

4. Atomic number is the number of proton for an atom of an elements.

5. All elements does not have the same types of atoms because every elements having their own atomic number that correspond to their number of proton. Since the number of proton equal to the number of electrons, bigger the atomic number will indicate more and more shells it has.

6. Free electron is the electron that is located in conduction band. The electron is initially located at the valance band before receiving thermal/external energy. Hence, the electron that jump from valance band to the conduction band is called free electrons.

7. Shell is a layer where the electrons seated. Every layer has their own energy level. The first layer that is the closest to nucleus is called first shell. The next shell will be 2nd, 3rd, 4th…..etc. shells.

8. Gold and Silver

9. Neutron and proton are the particles in the nucleus of an atom.

10. Valence band is also known as valence shell that is the outermost shell of an atom. In valence band, it can contain one up to eight valence electrons. If the valence electrons equal to one, it is nearly perfect conductor whereas if the valence electrons equal to eight it is insulator. So, we know that of producing an insulator the valence electrons must be equal to eight. There is a case where the valence electrons equal to four. In this case it is a semiconductor. In term of conductivity of an element, it depends on the number of electrons located in its valence band. In fact, conductivity is proportional to one and inversely proportional to the number of electrons in valence band (number of valence electron). Therefore, the higher conductivity correspond to the lesser its valence electrons and vice versa. In order to know an element is in which type, therefore we have to refer to their atomic number. Then calculate how many shell it has and how many electrons in every shell. The formula to calculate maximum number of electrons in every shell is N=2n^2, where n is the shell number.

11. For semiconductor, the electrons in their valance band is equal to four.

12. N=2n^2

n = number of shell = 4

N = 2 x (4)^2 = 2 x 16 = 32

Therefore, the maximum number of electrons in fourth shell is 32.

13. TRUE

14. Conduction band is located outside the valance band.

15. Energy level is the level of energy at a certain shell. Energy level for the outermost shell is higher than the inner shell and the innermost shell.

16. Energy gap is basically the gap of energy between two shells. It is also the amount of energy required for valence electron to jump from its valence band to the conduction band.

17. Intrinsic semiconductor is a pure semiconductor without any impurities added in.

18.

Insulator	Semiconductor	Conductor
The material that does not conduct electrical current in a normal condition.	The material between conductor and insulator.	The material that easily conducts electrical current.

 

19. Germanium only required small amount of energy to escape from their atom because it has smaller energy gap compared to silicon.

20. FALSE

21.TRUE